Apparatus for tube tapering and reforming a drawing ring

ABSTRACT

Apparatus for reducing the diameter of an expanded tube-tapering drawing ring after the ring has been enlarged by tapering a tube and a combination tube-tapering and drawing ring reducing apparatus. The drawing ring is forced through a tapered cylinder to reduce both the outside and inside diameter while the axial length is maintained substantially constant. A tube-drawing apparatus has a rotating head for holding drawing rings and indexing the drawing rings at a plurality of operational stations which include apparatus for tube drawing, annealing the rings, cooling the rings, and reducing the diameter of the rings.

United States Patent [72] Inventor John W. Hinshaw Garden Grove, Calif. 21 Appl. No. 805,581 [22] Filed Mar. 10,1969 [45] Patented July 20, 1971 [73] Assignee The Battelle Development Corporation Columbus, Ohio [54] APPARATUS FOR TUBE TAPERING AND REFORMING A DRAWING RING. 2 Claims, 9 Drawing Figs.

[52] US. Cl 72/354, 72/370, 76/107 [51] Int. Cl 821d 22/10 [50] Field of Search 72/354, 370; 76/ 107 l [56] References Cited UNITED STATES PATENTS 2,172,044 9/1939 Bowers 72/354 2,364,005 1 1/1944 Simons 76/107 A 2,367,942 1/1945 Harman 72/370 3,165,199 1/1965 Tlaker 72/354 Primary ExaminerRichard J. Herbst Attorney-Gray, Mase and Dunson holding drawing rings and indexing the drawing rings at a plurality of operational stations which include apparatus for tube drawing, annealing the rings, cooling the rings, and reducing the diameter of the rings.

PATENTEU JUL20I971 3593559 Fig. 2

JOHN W. HHHHH AW NTOR PATENTEU JUL20 I97] SHEET 2 BF 6 JOHN W. HINSH AW INVENTOR BY MN .\LE)1MMM,

ATTORNEYS PATENTEB JULZO ran 5 9? 5 5 saw 3 BF 6 JOHN W. HINSHAW INVENTOR ATTORNEYS PATENTED JUL20 I97! SHEET U, 0F 6 JOHN W. HINSHAW INVENTOR ATTORNEYS APPARATUS FOR TUBE TAPERING AND REFORMING A DRAWING RING CROSS REFERENCE TO RELATED APPLICATION The drawing ring described herein and the method for tapering a tube are described in US. Pat. No. 3,327,513, enti tled Method and Apparatus for Working Metal; filed Feb. 12, I965, and issuedJune 27, I967.

BACKGROUND OF THE INVENTION the diameter of the mandrel increases,the inside and outside:

diameter of the drawing ring increases. Ordinarily, the drawing ring would be discarded, but this invention includes apparatus for reclaiming the ring so that it is suitable for subsequent tube tapering operations. The invention provides for considerable savings in drawing ring material especially where larger drawing rings are used for tapering such items-as, for ex ample, sail masts and light poles.

The invention lies in as essentially new field since it relates to the expanding drawing ring and is anextension of the novel method and apparatus described in [1.8. Pat. No. 3,327,513. The drawing ring reducing apparatus is used to solve a substantially unique problem, that of returning a die to its originalform. Since, in the strict sense, a die does'not change its shape or size, the apparatus of this invention is for the recovery of a disposable die.

2. Description of the Prior Art Tube drawing is a well-known art. Drawing and tapering or reshaping tubing is a relatively difficult process. In order to solve some of the problems involved, prior art methods have relied on various shapes and sizes of dies i ncluding dies made up of sections fitted together to produce'a desired shape.

As for the reforming apparatus of thisinvention, there are numerous methods and apparatus in the art for forming dies but little description of recovering a used die since once constructed a die usually has a uniform shape. There is apparatus for the original forming of dies from blank pieces of metal, extruding metal to form a die, but the apparatus of this invention neither reforms the drawing ring from a blank nor is it extruded.

SUMMARY Apparatus for reducing the diameter of a drawing ring comprising a block having a cylindrical cavity, the cylindrical cavity having a large diameter section and a small diameter section connected by a tapered section, the drawing ring being positioned inside the large diameter section; a rod having a central axial projection positioned in the small diameter section; and a ram positioned in the large diameter section for moving the drawing ring across the tapered section into the smalldiameter section thereby reducing the outside diameter of the drawing ring from the diameter of the large diameter section to the diameter of the small diameter section and reducing the inside surface of the drawing ring to substantially the shape of the central projection on the first rod.

Also, apparatus for drawing and tapering tubing comprising a rotating plate having means for mounting a plurality of drawings rings, the plate being rotated by indexing means to position each drawing ring at an operational station. The stations include means for drawing a tube through a drawing ring and means for annealing, cooling, and reducing the diameter of the drawing rings.

It is an object of the present invention to provide apparatus for recovering expanded drawing rings for reuse in tapering tubing.

Another object is to provide apparatus wherein, once supplied with expandable drawing rings, the drawing rings are reformed to continuously provide drawing rings for drawing and tapering tubing.

Other objects and advantages of the invention will be apparent from the drawings, the specification, and the claims included herein.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. la is a perspective view ofa drawing ring as it appears after having been used to taper a tube;

FIG. 111 is a perspective view of a drawing ring before tapering a tube or after having been reformed from its shape in FIG. la;

FIG. 2 is a sectional view of apparatus for reducing the diameter of a drawing ring and 'having a drawing ring in position for diameter reduction;

FIG. 3 is a sectional view of the apparatus of FIG. 2 showing the position of the apparatus after the diameter of the drawing ring has been reduced;

FIG. 4 is a plan view of the main portions of apparatusfor continuously tapering tubing andreforming the drawing rings;

FIG. 5 is a sectional view in elevation taken along-the lines 5-5 of FIG. 4.

FIG. 6 is a sectional view of the ring reforming means shown as a part of the apparatus of FIGS. 4 and 5 and showing the drawing ring in position for reforming.

FIG. 7 is a sectional view of the apparatus of FIG. 6 showing the drawing ringdiameter reduced; and g FIG. S-is a sectional view of the apparatus of FIG. 6 showing the apparatus repositioning the reduced diameter drawing ring in the revolving head of the apparatus of FIGS. 4 and 5.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the drawings, the same reference numerals are applied'to identical parts in all embodiments and such identically numbered parts are substantially identical in structure, function, and operation. Therefore, to eliminate confusing duplication, these parts, their interrelationship and their function will be described only in conjunction with a single embodiment, such description applying to all embodiments where these parts ap pear.

Referring to FIG. la the drawing ring 11 has been used to draw and taper a tubing. The drawing ring hasa curved entrance [3 having a rim 14, an exit 15, an inside surface l7, and an outside surface 19. Both the inside surface 17 and outside surface 19 will have a diametersize vary with the drawing and tapering operation that was performed on the tubing. The drawing ring actually irons the tubing metal over the surface of a mandrel and the final diameter and shape of the mandrel determines the diameters of the inside and outside surfaces I7 and 19 are particularly the shape of the inside'surface l7. In-the example drawingring 11 shown in FIG. la the final portion of the mandrel used for tapering the tube has a tapered hexagonal shape. Thus, it should be noted that the expanded drawing ring, within limits, may have a variety of shapes and sizes. The constant factors are its axial length and the volume of the metal that makes up the ring. The diameter of the entrance rim 14 also remains substantially constant and preferably, the mandrel diameter is maintained at a size that is less than the diameter of the rim-14.

FIG. lbshows aiperspective view of the drawing ring 11' as it is first constructed'of after'the diameter reducing operation. The diameter of the inside surface 17 has been reduced to the small diameter of the tube'to be tapered and the diameterof I the outer surface is substantially equal to the diameter of the FIGS. 2 and 3 show apparatus for reforming the used drawing ring 11 as shown in FIG. 1a to the shape of the drawing ring 11' shown in FIG. 1b. A forming block 21 is provided with cylindrical cavity 23 having a large diameter section 25, and a small diameter section 27 connected by a tapered section 29.

The ring 11 is placed between a rod 31 and a second ram 33 and positioned in the large diameter section 25 as shown in FIG. 2. The rod 31 has a central axial projection 35 whose outer surface 37 conforms to the desired shape of the inside surface 17 of the drawing ring 11. The shape of the surface 35 may be described as a frustoconical section with the slanted surface concave. Preferably, the projection 35 has a threaded end 39 that engages a central threaded opening 41 in the ram 33. Connecting the rod 31 and the ram 33, although not absolutely necessary, has some advantages in that it maintains a constant distance between the rod 31 and ram 33 and allows the ram 33 to be used to pull" both the rod 31 and drawing ring 11' from the cavity 23 after the reforming operation is complete. The ram 33 is constructed with a large end 43 and a smaller end 45 surrounded by an elastomer 47. The diameter of the large end 43 substantially corresponds to the diameter of the large diameter section 25 and the diameter of the small end 45 substantially corresponding to the diameter of the small diameter section 27. A space 49, is provided between the surface of the cavity 25 and the surface of the ram 33 for the elastomer 47 to flow into the ram 33 is moved toward the small diameter cavity 27 FIG. 3 shows the ring 11 after having been moved across the tapered section 29 which forces the outside ring surface 19 to conform to the diameter of the small diameter cavity 27 and the inner surface 17 to conform to the shape of the surface 37 of rod end 35. The space between the ram 33, rod 31, surface of cavity 27 and the surface 37 conforms to the final desired shape of the ring 11. Preferably the rod 31 and ram 33 are moved through the cavity 23 by a force on the ram 33 (now shown) but the block 21 may also be passed over the rod 31 and ram 33.

FIGS'. 4 and show features of the apparatus 50 for tapering a tube while simultaneously reforming the drawing ring and FIGS. 6 through 8 show the details of the reforming station. Referring first to FIGS. 4 and 5, a frame 51, having longitudinal members 53 (preferably mounted on legs, not shown) at tached to cross members 55, supports a disc-shaped head 57 that is rotatably mounted on a bearing 59 on axle 61. Between each of the operations performed simultaneously by the apparatus 50 the head 56 is rotated to position and index the drawing rings at new station. The rotation is accomplished by suitable means such as a gear 63 engaging gear teeth 65 on head 57, gear 63 being rotated through an axle 67 connected to power source such as motor 69. Indexing is controlled by a cam 71 on axle 67 having a projection 73 that engages a microswitch 75 connected to motor 69. In the embodiment shown, gear 63 is selected so that one rotation of gear 63 rotates head 57 through one-sixth of a complete circle since six drawings rings 11-11 are mounted in the head 57.

At the beginning of each tube-drawing operation, a drawing ring 11' suitable for tapering a tube is indexed to receive the point 77 of tube 79, and for convenience this position shall be referred to as the first station. The point 77 passes through the drawing ring 11' and is engaged by suitable gripping means such as a pair of jaws 81 having slanted edges 83 engaging the slanted interior sides 85 of a retaining box 87 (the box 87 is turned up on its side for convenience in showing the various parts). A drawing arm 89 (attached to hydraulic means, not shown) is supported by a mount 91 having a slide 93 mounted on a rail 95. As the drawing arm 89 moves and pulls the tube 79 through the drawing ring 11, the tube diameter is reduced to confon'n to the shape of the tapered mandrel 97 positioned inside the tube 79. The drawing ring 11' expands as it encounters the increasing diameter of the mandrel 97. Also, if the mandrel 79 has a tapered hexagonal shape, the tube 79 is conformed to that shape and the inner surface 17 of the drawing ring 11. A guide 99 mounted on rail 101 is provided to keep the tube 79 aligned with drawing ring 11. A fixed plate 103 is mounted next to head 65 and holds the drawing ring 11' in position during the drawing operation.

After the drawing operation is completed (and the drawing ring 11, as shown in FIG. 1b, has assumed a shape of the drawing ring 11 so shown in FIG. 1a), the tapered tube and mandrel 79 are withdrawn from the ring 11. The head 65 is then rotated and indexed so that the ring 11 is moved to the second station. Depending upon how the stations are arranged, the head 57 could be rotated in either direction, but as the stations are shown in FIGS. 4 and 5, the rotation is counterclockwise as viewed in FIG. 5. The ring 11 is annealed at the second station by heaters 105-105 (partially hidden from I view in FIG. 4 but similar heaters are indicated at the fifth stathird station and is cooled by suitable means such as an air nozzle 109 mounted on plate 107. The fourth station is the reforming station while the fifth and sixth stations are annealing and cooling stations, respectively.

The fourth station is shown more particularly in FIGS. 6 through 8. The ring 11 is held in the head 57 by four arcuate holder 111 each attached to a rod 113 and urged toward the ring 11 by resilient means such as a spring 115. Two plates 117-117 are affixed to the head 57 and provide a cylindrical cavity 119 for the spring and to guide the rod 113.

The block 21 is attached to plate 107 and a block 21 is attached to plate 103 and is added to provide a cavity 25 as a guide and place for rod 33 to be positioned out of the way during rotation of head 57. After the head 57 has rotated and the ring 11 is positioned between the cavities 25 and 25 solenoid 119 is activated and operates valve 121 to supply hydraulic fluid (from a hydraulic pressure supply source, not shown) to hydraulic cylinder 123 which, through hydraulic rod 125 moves the ram 33 and ring 11 into large diameter cavity 25.

The ring 11 is forced across the tapered section 29 and against rod 31 and the surface 37 of projection 35 (FIG. 7). The end 39 of projection 35 fits into an opening 41' in ram 33. Solenoid 119 is activated in the opposite direction (operating valve 121 and cylinder 123) to withdraw ram 33. Simultaneously solenoid 127 is activated operating valve 129 to supply hydraulic fluid to hydraulic cylinder 131 forcing rod 31, through hydraulic rod 133 to follow ram 33 back out of cavity 25 and reposition the ring 11' in the holders 111-1 11.-

Just before the rod 31 repositions the ring 11 in the holders 111-111, an enlargement 135 contacts a microswitch 137 activating solenoids 139-139. Each solenoid operates a detent pin 141 that it forces against rod 31. When rod 31 has progressed far enough to reposition ring 11 in holders 111-111; the detent pins 141-141 each drop behind a shoulder 143 on a stripper bar 145 slideably mounted on rod 31. Each stripper bar 145 is urged away from ring 11 by resilient means such as the spring 149.

When solenoid 127 is reversed (reversing hydraulic cylinder 131) to withdraw rod 31, the stripper bars 145-145 remain against ring 11' as the rod 31 backs away as shown in FIG. 8. This assures that the ring 11' is freed from any tendency to bind on the surface 37 of projection 35. As soon as enlargement 135 clears the microswitch 137, the detent pins 141-141 are withdrawn and the stripper bars 145-145 snap back flush with the rod 31. The ring 11 is now ready to move to the fifth station for annealing and then to the sixth station for cooling.

It will be understood of course, that while the forms of the I invention herein shown and described constitute the preferred embodiments of the invention, it is not intended herein to illustrate all of the possible and equivalent forms or ramifications of the invention. It will also be understood that the words used are words of description rather than of limitation and that various changes such as changes in shape, relative size, and arrangement of parts may be substituted without departing from the spirit and scope of the invention herein disclosed.

IClaim and tapering tubing comprising:

a. A block having a cylindrical cavity, said cylindrical cavity including a first section of selected diameter, a second section of a diameter smaller than said first section, and a tapered section connecting said first and second sections, said drawing ring being positioned in said first diameter section;

a rod having a central axial projection in a frustoconical shape with the slanted surface concave, said rod having a diameter corresponding to said second section; and

c. a ram positioned in the first section of said cylindrical cavity, said rambeing the diameter of said second section and covered with an elastomer of sufficient thickness to increase the diameter of the composite ram to that of the first section for moving said drawing ring from said first section across said tapered section into said second section and against said rod thereby reducing the outside diameter of said drawing to conform to said second section and reducing the inside surface of said drawing ring to conform substantially to the shape of said central axial projection.

2. Apparatus for reforming a drawing ring used in drawing and tapering tubing in accordance with claim 1 wherein said rod and ram are spaced at a fixed distance from one another during the reforming of the drawing ring by a connection between them.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent N 3, 593, 559 Dated Julv 20. 1971 lnventofl John W. Hinshaw It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, line 30, "as" should read "an" Column 2, line 58, are" should read "and" line 70, "of" should read "or" Column 3, line 47, "56" should read "57" Column 5, line 4, after "of" insert a line 9, should read "b. a"

Signed and scaled this 14th day of January 1972.

(SEAL) Attost:

TDJARD ILFLETCI'IEM, JR, ROBERT GOITSCFL 1;

Attesting Officer Acting Commissioner of Patents FORM 5 0-1050110459) USCOMM DC uoanhpeg u s oovuumim "name onlci ml o-au-nl 

1. Apparatus for reforming a drawing ring used for drawing and tapering tubing comprising: a. A block having a cylindrical cavity, said cylindrical cavity including a first section of selected diameter, a second section of a diameter smaller than said first section, and a tapered section connecting said first and second sections, said drawing ring being positioned in said first diameter section; a rod having a central axial projection in a frustoconical shape with the slanted surface concave, said rod having a diameter corresponding to said second section; and c. a ram positioned in the first section of said cylindrical cavity, said ram being the diameter of said second section and covered with an elastomer of sufficient thickness to increase the diameter of the composite ram to that of the first section for moving said drawing ring from said first section across said tapered section into said second section and against said rod thereby reducing the outside diameter of said drawing to conform to said second section and reducing the inside surface of said drawing ring to conform substantially to the shape of said central axial projection.
 2. Apparatus for reforming a drawing ring used in drawing and tapering tubing in accordance with claim 1 wherein said rod and ram are spaced at a fixed distance from one another during the reforming of the drawing ring by a connection between them. 